Art of carburation



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ROY E'. ENSIGN, OF PASADENA, CALIORNIA., ASSGNOR .TO AENSGN CQARBURETOR COMPANY, OF LOS ANGELES, CALFORNIA, A CORPORATION OF CALIFORNIA.

ART OF CARBURATION.

Applcationiled November 25, 1919. Serial No. 3l.t0,658,

An object of this: discovery and invention y' is to control in a novel and effective manner,

the idling mixture in, that class ofy carburetor in which all the liquid fuel in the fuel pas- 5 sage flows downward during all phases' of carburetor operation, and at the same time provide for acceleration upon ,opening of the throttle; and in carrying out this invention, l make provision in that type of carburetor using a down flow fuel passage between the 4float chamber and the inixing chamber, whereby l. cause the fuel flowing in such passage during idling, to form a seal at the lower end of-'such passage, and thereby pro- .vide kmeans to cause an accumulation of fuel in such passage, and l make use of the sealing of the lower end of such fuel passage by checking the liquid fuel at thelower end ofjits path to ymake it possible to apply the modified high depression fof the engine intake to enrich the mixture during idling and to use the accumulated fuel thus obtained for acceleration as above stated. y

n object of the invention is to increase the proportion ofk fuel to air in the mixture during idling action of the engine so as to permit the motor to function well during.

the lower 'ispeeds A vln carrying out this invention l use only :io one passage and cause operation buv-applying boththe force of 1gravity and of suction to deliver' fuel under all conditions of operation in a continuously downward path, to the mixing chamber, and l make provision direction of gravity to cause the fuel to. flow down through a passage into the mixing chamber, and increase sucn suction during idling above that imposed by the air flowing in such chamber.

ln the type of carburetors which l have employed in carrying out this invention, there is produced by vertical action of air in the mixing chamber, a depression which is 5 applied to maintain a constant ratio between whereby the effective -air pressure or suction? air pressure or suction upon the fuel,K in the y I provide an internal combustion engine f carburetor comprising, in combination with .a b'y-pass whereby suction of the engine on the engine side of the throttle is applied,

- during the idling period to increase the suction on a restricted fuel orice through which all the-fuel supply passes to the lair supply throughout the entire-,range `of operation, a downwardly extending fuel passage through which all the fuel passes during all conditions and phases of such operation. An object of the invent-ion is to furnish additional fuel during rapidacceleration of Y the engine, and I provide at the lower end of said downwardly extending fuel passage, a pocket adapted to accumulate such addition! al fuel for such purpose 4and arranged to be sealed by such accumulation to make it possible to increase the richness of during idling,

The discovery and invention is an provenient in the art in thatl increase the the mixture` depression in the suction chamber over that ,i

imposed by the normal operation of the air fiow through the proportioning element of the carburetor to such an extent as to reverse the effective pressure of the air in the.

suction chamber, through the fuel vpassage to the mixing chamber, thus causing momentary cessation of fuel delivery to the main airstrearm and an accumulation within said fuel passage, of a seal or column of fuel, the

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height of which seal determines the richness of the low speed mixture; and in this invention l provide means for controlling the height of said column of' suspended fuel, and thereby controlling the richness of the mixture.

AnotherA object is to provide an adjustment! whereby the depression applied as above mentioned can be practically regir Other objects, advantagesand features of invention may'appear from the accompany ing drawing', the subjoined detail description and -theappended claims.

ln order tomore' particularly set forth the discovery and invention, reference will now be had to the accompanying drawing which ice in idling positionand the liquid levels are shown in position occupied when the engine is at rest. Lines el, Figs. 2, 3, and indicate the plane of section.

Fig. 2 is a detached fragmental elevation of the delivery end of the carburetor shown i in Figi-1, looking into the suction passage.

Fig. 3 is afragmental axial section of the lcarburetor shown in Fig. 1 at that period of operation during which low' idling speed is maintained and a charge of liquid fuel is held suspendedby regulating the application ternal combustion engine.

of depression in the suction chamber a preparatory to an increased fuel flow for accelerating the engine when the throttle is opened..

Fig. 4. is an enlarged fragmental section of -2'5 the suction -fuel outlet with liquid fuel charge suspended as 'shown' in Fig. 3.

Fig. 5 is a section on lines m5, Figs.- 1 and 2,

omitting the center stem that forms a part of the suction conduit. Parts are broken away to more clearly show the conduit.

It is understood that different forms and I arrangements of means mayV be provided whereby my newly discovered method may be performed; but the foregoing drawing is deemed suiiicient to fully explain the operations and to illustrate the best form in which I have embodied the means I employ in carrying out my invention.

The suction chamber ais connected withl the constant level'fuel vsupply chamber through the fuel orifice c, and extends above, and is open to, the fuel passage l-which is shown in the drawing as having an enlarge,

ment or chamber 2 at its lower end, and com.` Inunicates through a trap t, and the fuel jet 3, with the mixing chamber Il that has an air inlet 5 and a mixture outlet 6, the latter Mopening into the suction passage 7 which is connected to the intake manifold 8,-of an in- 9 isl the throttle between the suction passage 7 and the mixture outlet G. p

A by-pass for controlling the depression' on the fuel orifice during idling is provided', leading from the suction chamber a `above the fuel level to the suction passage 7; and said by-pass is shown as comprising a suction tube 10, leading from above the overow inlet 11 of the fuel passage to a duct 12 that opens into an annular chamber 13 which communicates with the suctionV passage. 7 through a bore 14 and by-pass port v15.

Said suction chamber a also has a restricted communication with the atmosphere, and in Fig. 1, such communication is shown as being effected through an air port 16 and an equalizing tube 17 that/communicates with the air inlet 5 and is arran ed to insure that pressure conditions in the oat chamber are the same as those at the air intake 5 of the vortex chamber. The restricted fuel orifice aopens from the constant level chamber b into the suction chamber a below the constantliquid level 18 of such chamber, and the parts are so constructed and ,arranged that the overflow inlet 11 is somewhat above the constant liquid level '185 The intake of suction tube 10 is at such a height', above the liquid level 18 as to prevent any liquid fuel from being sucked into the suction tube 10 at any time by the operation of the engine.

The cork float 19 is of the usual type to close the fuel valvev 20 against the pressure ofthe fuel supply. 21 is aA priming plunger adapted to depress the float 19 to open valve 20 when desired. Y'

The adjusting sleeve 22 'is provided at thc top with a milled head to make it convenient to rotate the same to adjust the opening of the orifice c. in fixed position by means of the retainer spring 23.

Thel adjusting'passage 24 connects the bypass and the mixture outlet 6, of the mixing chamber4. i

The adjusting passage 24 is controlled biya screw operated valve 25 retained in adiusted position by the retainerv spring 26..

from the balance tube 17 to the surface of.

the fuel in the constant level fuel chamber. During engineoperation at any speed, the usual vortex is formed in the mixing cham- 4ber by air sucked through from. the inlet 5,

but with the former carburetor'of, this type the suction produced on the fuel jet port at 3 b y vertical action, is insufficient to maintain the operation of the engine at low idling speed; but by my improvement the fuelv feed during idling, is made positive, and fuel is accumulated in the fuel passage and held therein until the throttle is opened,

Aand is thereuponreleased or discharged into the mixing chamber and celerate the engine.

then serves to ac- Starting with the engine running under load and the proportioning ,and mixing sion, acting through the'port 15 and through lne vllO

neeaese the* idling ley-pass creates in. the suction chamber a, a depression greater than'thatat the fuel jet 3 imposed by the vertical action in the mixing chamber 4.-, atthe lov:r speeds of the motorwhen idling, in spite 'of the fact that the suction chamber a is open to the atthrough the fuel passage 1 and its 'enlargement 2, and communicates through the jet port 3 with the air in the mixing chamber L1.`

rlhis excess depression in a above that in .Y`

An'nnished, and the accumulated fuel will im- 1 mediatelybe discharged. and carried in with the mixing' chamber when idling, will cause,

an increase in fuel vflow through the orifice 0f;

an increase in air flow through the restrict-ed port 16, a momentary flow of air through the jet port at 3 from the mixing chamber,

and an accumulation of fuel in the chamber'` 2 and the fuel passage l against the force of gravity, thus forming a seal as shown in Fig. 4, and filling the fuel passage until these forces come to equilibrium; that is, until the height of this column of fuel becomes sufficient to balance the suction that is applied through ythe by-pass during idling; andoperates against the restricted air port 16 and against the depression inV the vortex chamber; fuel continuing to flow-through c 4under this depression, will fall down to the surface of the upper end e, of this column and will drop out of the jet 3 as shown in Fig. 3, and will flow down along the 'bottoml of the mixture outlet 6;` some of it flowing twill flow through orilice c.

through the adjusting passage 24, Vand on past the throttle into the engine. The height of this column of fuel.is regulated by means of valve 25, opening or closing thispassage, adjusting the amount of air and fuel which ln practice the port l5 being operated on by the high vacuum beyond the throttle, can

be relatively small and may not be larger than H-,th of an inch depending-upon the design of the carburetor while the port 16 is somewhat larger and would be at least fty per cent greater in area than the port 15 in this particular type of carburetor.

Adjustment of the valve 25 will control 'the height, as at e, of the column of accumulated fuel in the fuel passage 1 and the fuel flow for the idling mixture.

fuel is a measure of the pressure operating vto increase the flow of fuel through the oribecause the pressure necessary to raise the fuel to the point of overflow at 11 is toovlarge a percentage'l of the total depression existing in chamber a during idling. An idling or low speed operating mixture must be slightly richer than a full load mixture to obtain smooth operation at such low speedse The lt will be read- A ily seen that the height of this column of4 over-How inlet 11 isv necessarily some distance above the normal fuel level in oredr to prevent leakage, therefore, 'a correspondingly higher depression in low speedv range must be maintained in the suction chamber a.

flhis accumulation of fuel between the jet 3^ and some point in the mixture passage 1 becomes available for rapid acceleration of the motor or engine when changing from idling'to higher speed, or load; for, upon opening the throttle 9, the excess, depression applied through the by-pass is instantly dithe rush of new air to supply the engine at the first instant' of acceleration, until normal yflow is established for the new speed. At no time during all of these operations `is there any fuel passing throughthe upper end of the tube 10, and nothing but air is carried by this idling by-pass until it is supplied with fuel through some vent, such as the adjusting passage 24, which may pick up fuel; so that in general operation this'idling adjust- 4'mentiras no effect upon the mixture until the throttle is nearly closed; and all the fuel, all

the time, whether under load or idling, flows rect at all speeds when fuel `orifice c is adjusted at any speed; and the difficulty of obtaining correct mixture at idling is overcome by having a predetermined fuel oriiice c and varying the pressure on thatoritice to cover the idling speed. lf independent means were introduced to produce the idling mixture, it would supply more or less fuel throughout the whole range and would supplement and interfere with the correct mixture produced in the mixing chamber '4. With this improvement a small movement of the throttle from the idli position removes any special pressure on t nel orifice, leaving the carburetor to the normalaction and this is especially helped by using the air and fuel flowing within the carburetor for supplying the adjusting passage Q41.

@ne important reason foigsupplying thisvent from the inside of the carburetor is,

that if atmospheric air is taken in at this point/during idling, it disturbs the proportion throughoutthe whole range of the .carburetor on account of the vent 24 being constantl,` open to new air; and a second washer and'there should be only one connection to such stove or washer; Vtherefore* all vents and controls should be supplied from the one air inlet 5.

Such stove or air .washer willcause a varia-ble depression atthe intake 5, which `is compensated for by-means of air supplied through equalizing'tube 17 to air port 16,

and to the surface 18 of the'fuel through the hole 27. If air from outside the .carburetor were admittedto 24 these variable pressures would upset the proportioning. y

-The heavy fractions of the fuel that 'are thrownon the walls of the mixing chamber et finally escape thoroughly atomized and under considerable pressure through the ports 9() into the mixture outlet 6. The

pressure at which the heavy fractions of fuel are discharged into the mixture passage may` amount to one-half pound per square inch atfull load and at such pressures air flowing with the fuel. in the mix-` ing 1chamber causes violentl atomization of the fuel passing through the ports v90.

Auxiliary accelerating means are provided comprising a sump 91 adapted vto ac-Y cumulate fuel from the mixture outlet and a passage 92'leading from the bottom ofv said sump .to a point beyond the throttle. An overflow is provided Afor the sump'to prevent flooding of-the engine to which the carburetor'is attached and consists of an outlet 93 drilled in the boss94: the top of which is slightly below lthe bottom of the mixture outlet as shown in Fig. 2.

I claimt- 1. A carburetor comprising a suction pas` sage; a mixing chamber provided with an air inlet and having a mixture outlet open to the suction passage; a throttle to control the mixture outlet; .a constant level fuel chamber; a suction chamber; af re" stricted fuel orifice to delivenliquid from the fuel chamber to the suction chamber; a.' fuel passage leading downwardly from the suction chamber andopening into the mixing chamber below the level of the re-f stricted fuel orifice; a conduit open be'yond the throttle and forming a constantly open communication between the suction passage' chamber; a suction chamber;` a `restricted fuel orifice to deliver liquid fromthe fuel chamber to the suction chamber; a fuel pas-- suction passage to cause the formation of a seal at the trap in the fuel passage, thus `lniali1ig possible a richer mixture 'during idle operating; and a restricted air port con- -stantly open td the suction chamber.

3. A carburetor provided with a constant levelv fuel chamber ;K a suction passage; a suction chamber supplied with fuel from the constant level chamber through a restricted orifice; and-with air from a restricted air port; a mixing chamber; an air inlet and 'a ymixture outlet.; a throttle controlling the mixture outlet; a fuel passage leading downward yfrom the suction chamber to themix ing chamber to supply fuel from said suc- .tion chamber to said mixing chamber; a by-pass leading from the suction chamber at a point well above. the fuel level, tov the suction passage to apply in the suction chamber at a closed position of the throttle a depression from beyond thev throttle to sustain a column of fuely in the fuel passage against the force of gravity; and means'. for

controlling the suction applied in said chamber through said lay-pass.

4.11 carburetor provided withl a constant level fuel chamber; a suction passage; a suction chamber supplied withfuel fromthe constant level chamber through a restricted orifice, and with air from-a restricted air port; a mixing chamber; an air inlet and a mixture outlet; a throttle controlling the mixture outlet; a fuel passage leading downward from the suction chamber to the mixing chamber to supply fuel from said suction chamber to said mixing chamber; a by-pass leading from the suction chamber'at a pointl well above the fuel level,` to the suction passage to apply in the suction chamber at a closed position of the throttle a depression from beyond the throttle to sustain a column of fuel in the fuel passage against the force of gravity; and a valve controlled 'passage to admit u controlled amount of mixture to' the bypass to control the suction in the by-pass `and adjust the depression in the suction chamber.

In testimony whereof, I have hereunto set my hand at Los Angeles,v California, this 19th day of November, 1919.

i ROY F. EN SIGN. 

